Nervous System HAP

Function of the nervous system

coordinate body systems by receiving and sending messages while keeping homeostasis

3 functions of the nervous system

sensory: receives info, Integrative: determines where info is sent, Motor: receives messages

pairs of nerves in PNS

31 pairs of spinal nerves, 12 pairs of cranial nerves (86 total nerves)

Somatic NS (PNS)

skeletal & voluntary

Autonomic NS (PNS)

Smooth muscles, glands, Involuntary

Parasympathetic NS (ANS)

rest and digest (peace)

Sympathetic

fight or flight (stress)

Part of neurons

Cell body, chromatophilic substances, dendrites, axon, myelin sheat, nodes of ranvier

microglial cells

Digest debris, kills and engulfs bacteria in immune response

Oligodendrocytes

make myelin sheath in central nervous system

Schwann cells

Form myelin sheath in peripheral nervous system

Astrocytes

connects blood vessels (capillaries) to neurons

Ependymal Cells

forms a membrane around tissue (structural)

Action potential steps

1. Neuron membrane @ resting potential.

2. Threshold stimulus is reached

3. Sodium channels open & depolarization: sodium ions diffuse inside

4. Potassium channels open & repolarization: potassium channels diffuse outside

5. Back to resting potential

Excitatory

type of neurotransmitter that increases permeability, increasing change for threshold to be reached

Inhibitory

type of neurotransmitter that decreases permeability, decreasing change for threshold to be reached

Acetylcholine

Neurotransmitter that stimulates muscle contraction

Dopamine

Neurotransmitter that regulates happiness and mood

Serotonin

Neurotransmitter that regulates sleep and mood

endorphins

Neurotransmitter that reduces pain and regulates mood

Agonist

molecule that mimics the affect that neurotransmitters has on the postsynaptic neuron

Antagonist

molecule that blocks the affect that neurotransmitters has on the postsynaptic neuron

Action potential

Quick electric character that is sent down the axon

SSRI stand for

Selective serotonin reuptake inhibitor

Selective Serotonin reuptake Inhibitor

a type of drug that inhibits the reuptake of serotonin, so that their levels will increase and treat depression and anxiety